Toroidal ion temperature gradient driven instability in plasma with shear flow

Abstract

The temporal evolution of the toroidal ion temperature gradient driven (ηi) instability in plasma with homogeneous shear flow is studied directly without the use of spectral expansions in time. The regimes of weak flow shear, which corresponds to the period of the low-to-high (L–H) transition and the regime of strong flow shear which corresponds to the stage of the developed transport barriers, were studied separately. In the case of weak flow shear stabilization of the toroidal ηi instability is more a mathematical artifact. In contrast, the region of the strong flow shear is stable against the development of the toroidal ηi instability and is impenetrable for the anomalous transport conditioned by the toroidal ηi instability developed in the inner part of the plasma.